This program provides opportunities for twelve predoctoral and five postdoctoral trainees to master the intellectual and technical skills needed for research careers in areas fundamental to cancer. Trainees, especially predoctoral level individuals, enter the program from undergraduate education and without a commitment to cancer-related research careers. The training introduces them to a wide range of areas important to the cancer problem, emphasizing biochemical and biophysical and molecular biological approaches. It aims to provide experience in designing experiments to formulate and answer research questions. This program has succeeded in producing individuals who contribute to the cancer research effort in their careers, and should continue to do so in the future. The training program takes advantage of the extensive resources in the biomedical sciences available within the Hopkins Medical Institutions, including the Hopkins Oncology Center. The training faculty prosecute research and provide training in the structural chemistry and function of nucleic acids, in bioorganic chemistry and enzyme reaction mechanisms; damage to DNA by carcinogens and environmental agents; the relationship of DNA repair to cancer; regulation of gene expression by antisense reagents; cellular processes involved in the synthesis, replication, transcription, repair, and recombination of DNA; biosynthesis of glycoproteins; control and regulation of gene expression; and signal transduction circuits and their control.